And the man bowed down his head, and worshipped the LORD. Bowed down his head, and worshipped - Two acts of adoration are mentioned here;
1. Bowing the head, יקד yikkod; and
2. Prostration upon the earth, וישתחו vaiyishtaehu.
The bowing of the head was to Rebekah, to return her thanks for her kind invitation. The prostration was to Jehovah, in gratitude for the success with which he had favored him.